Combined tire gauge and engine compression gauge



H. A. WALKER. COMBINED TJRE GAUGE AND ENGINE COMPRESSION GAUGE.

APPLICATION FILED sEPT.20. 1920.

1,438,798. -Pa ented. Dec. 12, 1922..

wwwv Patented Dec. 12, 1922.

nanny nnnnn'r WALKER, or sannuronro, 'rnrrns;

' COMBINED TIRE GAUGE AND ENGI NE COMPRESSION GAUGE.

Application filed September To all. a /tom it may concern: 1 1

Be it known that I, H RRY A BERT vl'iinnnn, a citizen of thellnited States, and a resident oi? San Antonio, in the county of Boxcar and State of Texas, have invented a new and useful Improvement in Combined Tire Gauges and Engine Compression Gauges, of which the following is a full, clear, and exact description.

Zvly invention relates to improvements in combined tire gauges and engine compression gauges, and it consists in the combinations, constructions I and arrangements herein described and claimed.

An object of my invention; is to provide a gauge which will accurately indicate the compression in a pneumatic tire, or the compression obtained in an engine cylinder, and in which the indicating stem is heldjpositively in any position to which it has been moved by pressure, so that it maybe read at leisure. I y

A further object of my invention is to provide a device of the type described in which the indicating stern may be readily released from its position and restored to its normalposition. j v 1 y A further object of my invention is to provide a device which is positive in action, and which is not liable to easily get out of order.

Other objects and advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawings, forming part of this application, in which- Figure 1 is a longitudinal sectional view of the device,

Figure 2 is an enlarged. sectional view of a portion of the device.

Figure 8 is aside view of the device as applied to an engine cylinder, and

Figure 4 is a section along the line 4i-4 oi Figure 1.

In carrying out my invention. 1 provide a base portion 1 which is in the nature of a screw plug, being threaded at 2 to enter a threaded spark plug opening. The plug is provided with a central passage 3, and is tapered along its bottom, as indicated at 4, for a purpose hereinafter explained.

A cylinder 5 is threaded at its lower and at its upper end, the lower end entering a threaded recess in the plug 1, and the'upper 20, 1920. Serial No. 411,464.

end entering a similar threaded recess in a cap 6. The cap 6 18 provided with a central threaded opening 7 rranged to receive a screw plug 8; The latter is provided with a head 9 and .hasan openinglO which extends through the head and through the body of the screw plug. The head is provided with a recess 11 in which is disposed a tooth or projection 12 which is held by a pin 13 or by any suitable retaining means. On the side of the head opposite the tooth 12 is a bore 141- in which is disposed a spiral spring 15 having a cap 16 at one end, and bearing at the other end on a screw plug 1 7. i

Arranged to pass through the opening 10 is. a stern 18 which is provided with numerals 19 toindicate the pressure, preferably in pounds per square inch. One edge of the stem 18 is provided with teeth 20 which are arrangedto engage the tooth 12. The lower end of the stem 18 is connected by means of a wrist pin 21 with a plunger head 22. Betweenthe plunger head 22 and the cap 6'is disposed a spiral spring 23. The plunger head 22 has a grooved stop member 24:: on its under side. From thetforegoing.description of the various parts of the device, the operation thereof may be readily understood. In as certaining the compression of the engine, the screw plug 1 is inserted in the spark plug opening, and the engine is either turned over by hand or the self starter is started with the ignition switch off. The air under compression will pass through the opening 3, and will. force the plunger head 22 upwardly against the tension oft-he spring 23. As the stem 18 moves upwardly, the teeth on the stern are held in engagement with the tooth 12. The stem will be forced as liar as the pressure will warrant. The pressure may be noted from the indicating marks 19, the tooth 12 holding the stem in position. When it is desired to restore the stem to its original position, all that is necessary is to press it toward the right in Figures 1 and,

2, compresing the spring 15 and freeing the teeth 20 from the tooth 12. The spring 23 will. then return the plunger head to its original position. The underside oi the plunger head bears a stop member 2% which isarranged to engage a spider 25 to limit the movement of the plunger head.

When the device is used for measuring the pressure of a pneumatic tire, the valve is,

inserted in the opening 3 and pressed inwardly until thevalve stem comes in contact with the spider 25, when the valve is forced open and the presure permitted to act on the plunger head 22, thereby moving the stem 18 to indicate the pressure within the I tube.

The tension of the spring 23 may be varied by turning the cap 6. It will be observed that the opening 10 in the screw plug 81is large enough to give the stem; 18 suflicient sion" of the spring 15. The device is positive in action and is easily operated.

1. A combined tire gauge and engine compression gauge comprising a cylindrical casing, an indicating stem slidable into and out of said casing, a spring for normally holding said stem within said casing, a plunger head secured to the stern for moving the latter against the tension of said spring, means for retaining the stem in its shifted position, and these carried at one end of said casing, said base being adapted to' b'escrewed into a spark plug opening and having a central opening therethrough adapted to receive a tire valve stem.

2; A combined tire an'd engine compres sion' gau e comprising a cylindrical casing, an indicating stern slidable through-one end of said casing, a plunger head pivotally connected with said stem, a spiral springvdisposed between said plunger head and one end of said casing, a series of tee'th'car'riled I by said stem arranged to engatge a portion of said casing, spring means or normally ing threads disposed on its outer surface adapted to screw into a spark plug opening, and a centrally located opening therethrou h adapted to receive a tire valve stem.

3. 1% pressure gauge comprising a cylindrical casing, a base secured to the casing at one end, said base having a central opening, a cap secured tothe-casing at the opposite end, a screw plug carried by the cap, said screw plug having an opening, an indicating stem arranged to slide through the opening-in the screw plug, a plunger head p'ivot ally secured to said stem, a spiral spring disposed between said plunger head and said cap, and means carried by said screw plug and arranged to engage a portion of the plug for holding the stem in its shifted positions.

l. A pressure gauge comprising a cylindrical casing, a base secured'to the casing at one end, said base having a central opening, ac'ap secured to the casing at the opposite end, a screw plug carried by the cap, said screw plug having an opening, an in dicating stern arranged to slide through the opening in the screw plug, a plunger head pivotally secured to said stem, a spiral spring disposed between said plunger head and said cap, a pivot carried by the stem on one side thereof, a fixed tooth carried by the screw plug and arranged to be engaged by the tooth on thestem, and spring'imeans for forcing said stem toward said fixed tooth. v

HARRY ALBERT WALKER. 

